Lock



Feb. l, 1938. D. D. MCA. Mor-'PITT LOCK Filed Aug. 25, 1.9556 2Sheets-Sheet 2 I f5 p5 92 A12 mfq;

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Patented Feb. 1, 1938 UNITED STATES LOCK Duncan Douglas McArthurMoffitt, Arapito,

Westport, New Zealand, assigner to The Mofiitt Automatic Lock port, NewZealand, a land Company Limited, Westcorporation of New Zea- ApplicationAugust 25, 1936, Serial No. 97,837 In New Zealand October 21, 1935 6-Claims.

This invention relates to latches for doors, and in particular motorVehicle doors and the like.

The object of the present invention is to en- 5 able the latch bolt tobe withdrawn and held clear of the face of the door, and to be releasedwhen the door is closed.

According to the present invention, a latch bolt is formed on the end ofa latch rod slideable in the latch casing, and normally tends to beprojected forwardly into engagement with a recess in the frame, whilemanual means are provided to retract the rod and bolt. A releasing rod rprojects through the hinged end of the door and is under tension of aspring which normally tends to project the releasing rod in a rearwardposition, so that as the door is opened this rod moves rearwardly. Aretaining pawl is pivoted in the casing and is adapted to engage andretain the latch rod in a retracted position, means being provided sothat when the door is unlatched, the retaining pawl will be actuatedthrough the medium of the releasing rod to engage the latch rod, butwhen the door is closed, such releasing rod will again actuate theretaining pawl in order to disengage it from the latch rod and permitsuch rod to be projected forward under the pressure of its spring.

In one form, a trip member is provided which is pivoted to the releasingrod, and adapted to fall into alignment with the said rod, and with arod controlling the pawl, this trip member being raised when the handleis initially turned in order to permit the retaining pawl to engage thelatch rod, but returns into position on the release of the handle, sothat when the door is being closed, the releasing rod will, through themedium of the trip member, actuate the pawl and so release the latchrod.

In another form, the retaining pawl is simply pivoted to a rod which isin turn pivoted to the releasing rod, the opening of the door enablingthe releasing rod to o-perate the pawl to engage the latch rod, but theclosing of the door causes the releasing rod to disengage the pawl andpermits the latch rod to be projected forward into position.

The invention will be described with the aid of the accompanyingdrawings, wherein:-

Figure l is a side elevation partly in section of the lock.

Figure 2 is a similar View but showing the position of the parts duringthe unlatching operation.

Figure 3 is also a similar View showing the position of the parts whenthe door is being opened.

Figure 4 is a cross section on line A-A Figure l.

Figure 5 is a cross section on line B-B Figure l.

Figure 6 is a plan showing a door partly open.

Figure 7 is an elevation partly in section of a slightly modied form ofthe lock.

Figure 8 is a similar view showing the position of the parts during theopening operation.

Referring to the drawings, and first to Figures l to 5, a latch rod Ihas a latch bolt 2 with a conical engaging endto enter a conical recessin a socket 3 within the frame 4, the bolt 2 and the rod I being adaptedto be projected forward into the recess by means of a coil spring 5 incompression between a pin and washer 6 on the latch rod I and a part 1of the lock casing, through which the end of the rod I is guided. Theother end forming the latch bolt 2 is guided in a socket 8 tted into anend member 9 of the door. In some cases the socket may form part of thelock casing. A lever I is fixed on a cross member or bar I I, to whichhandles I2 (see Figures 4 and 6) are secured upon the exterior of thedoor. This bar II is pivoted in the sides I4 and I5 forming the lockcasing, these sidesY being xed to the part 1 and to transverse parts I6and I1. The lever I0 has pivoted on its upper end a pawl I8 adapted toengage a shoulder I9 on the ro-d I. A coil spring 2li, attached to thelever I0 and anchored at a convenient point on the member 9 of the door,tends to retain the lever in the position shown in Figures 1 and 3. Aretaining pawl 2l is pivoted to the casing on a pin 22 which traversesthe sides I4 and I5, the other end of the pawl being pivoted to the endof a rod 23 slideable in the part I1. of the casing, and herein referredto as a pawl rod. 'I'he end of the pawl 2| is adapted to engage ashoulder 24 on the rod I. A releasing rod 25 slideable in the part 1 andin the end member 26 of the door, is normally adapted to be projectedrearwardly by a coil spring 21 in compression between the part 1 and awasher 28 and pin 29. A trip arm 30, pivoted to the releasing rod 25, isadapted to align with the pawl rod 23 and with the releasing rod 25, andis normally retained in alignment by a at spring 3| fixed to the rod 25and bearing on the trip arm 30.

The rear end of the releasing rod 25 passes through the end member 26and is adapted to strike the member 32 of the door frame, or anadjustable stop 33 set therein.

A coil spring 34 around the pawl rod 23 is in compression between thepart I1 of the casing and a washer 35 held against a pin 36. The hole inthe part I1, through which the pawl rod passes, is slightly larger thanthe rod, so that a little vertical movement of the pawl rod can takeplace to permit the arcuate movement of the pawl 2I. A bell crank lever31 forms a trip lever and is pivoted on a pin 33 in the sides I4 and I5of the casing. This trip lever is shown in Figure bifurcated, the endsof the forks 39 thereof having a pin 40 which will engage under the triparm 30. The other end of the trip lever is connected by a link 4| to thelever I0.

In operation, assuming that the door has been closed and the lockingbolt is in position, as 'inl Figure l, in order to retract the latchbolt 2 to open the door, a handle I2 is operated, and the lever I ismoved back and carries the rod I back to the position shown in Figure 2,thereby withdrawing the conically pointed. end 2 from its recess in theframe. At the same time, the coil spring 5 is further compressed. Thismovement also has caused the link 4| to operate the trip lever 37 andwill cause the trip arm 30 to be moved out of alignment with the rodsf23and 25, thereby permitting the rod 23 to travel rearwar-ds under theaction of the coil spring 34', and will cause the retaining pawl 2| toengage behind the tooth or shoulder 24 on the latch rod I, and retainthis'rod in its retractedposition.

' Upon the operator freeing the handle I2, the Vlever I0 andpawl V| 8will return, under the action of the spring'20, back to the normalposition, the link 4| returning the trip lever as'shown in Fig- YureslandA 3, but the trip arm 30 would .re-

main as in Figure 2. As the door is opened on its hinges, it will moveaway from the frame member 32l (see Figure 6) and the coil spring 2'!will `cause the releasing rod 25-to slide through thefr'ame 2liyand-carry back with it the trip arm 3|), which will then fall intoalignment with the pawl rod 23, as shown in Figure 3. The rearwardmovement of the rod 25 vwould be limited by a` collar or washer 42. Y Y

When the door is being closed, upon the'rear end of: the releasing Yrod25 striking the frame or stopV 33,'the trip arm 30 will be forcedforward and in turn will force forward Vthe pawl vrod 23 and thus rotatethe retaining pawl 2| backto the `position shown in Figure l', suchmovement disen- Y gagingY it from the shoulder 24; the rod moving back alittle forv this purpose. Once the rod' is released, it will, under thepressure of its coil spring 5, be shot forward and the conical end 2will enter the conical recess in the socket 3, and the mechanism willthen assume the position shown in Figure' 1. v

'I'he conical end of the bolt 'ensures that any play will be taken upand will thus prevent any tendency to rattle or looseness.

In Figures 7 and 8, a modification is shown, in that the trip arm 3|)with the trip lever is eliminated, the pawl rodv 23 being pivoted to thereleasing rod` 25'. l

In this case, the operation is that when the handle I2 is` rotated, theYlever I0 operates the pawl I8 which will engage the tooth I9 and car-Vries back the rod I as before. In this case, the

handlev would be retained inthe drawn-back po-V sition until the conicalend of the bolt 2Qis clear of the socket, by which time the releasingrod 25 will have moved back far enough (as indicated in Figure 8)toraise the point of the pawl 2| toY engage the shoulder 24. When thedoor is being closed, however, the releasing rod 25 will push forwardthe pawl rod 2'3-and will cause the retaining pawlr 2| to disengage fromthe shoulder 24 Y What I claimV isr- Y 1. In a latch for doors, acasing,a latch rod slidable Yin said casing, an engaging end to said rod, aspring normally tending to project said `latch rod forwardly intoengaging position,

means to retract said latch rod, a releasing rod projectable through thehinged edge of the door, k a spring to retain said releasing rod inprojected position, a retaining pawl pivoted in said casing toA engageand retain said latch rod retracted, a pawl rod pivoted to saidlretaining pawl and guided in alignment with said releasing rod, means toretract saidl pawl rodl rearwardly and operate said retaining pawl toengaging position with said latch rod, and meansvto disengage saidretaining pawl from said latch rod when said releasing rod is movedforwardly upon the closing of the door. 2'. In the latch as claimed inclaim l, a pawl rod pivoted. to said retaining pawl, and guided inalignment with said'releasing rod, said pawl rod pivoted to the forwardend of said releasing rod, so that when the door opens the saidwpawlspring to retain said releasing rod in a projected position, a retainingpawl pivoted in said casing to engage and retain said .latch rodretracted, a pawl rod pivoted to said retaining 'pawl and Vguided so asto be moved forwardly by the said releasing rod to disengage the pawlfrom said latch rod wheny the door is being closed, andY means wherebysaid pawl rod will permit the pawl to engage said latch rod upon theretracting move-A ment of said latch rod independent of movement of thereleasing rod. Y Y

5. A .latch as claimed in claim` I, a spring to retractrvsaid pawl rodrearwardly and operate said retaining pawl to engaging position withsaid latch rod, a trip arm pivoted to said ,releasing rod and adapted tofall into alignment with said pawl rod to disengagesaid retaining pawlfrom the said latch rod when saidy releasing rod is moved forwardly uponthe closing of the door, and means to raise said trip arm outofralignment with Said pawl rod to permit said pawl rod to moverearwardly and acuate said retaining pawl to en gage'said latch rod,said trip arm adapted to return into alignment with the pawl rod whenthe door is opened.

6. A latch as claimed .in claim 1, a spring to retract said pawl rodrearwardly and operate said retaining pawl to engaging position withsaid latch rod, a trip arm pivoted to said releasing rod and adapted tofall into alignment with said pawl rod to disengage said retaining Vpawlfrom the said latch rod when said releasing rod is moved forwardly uponthe closing of the door.

a trip lever pivoted in said casing, and forming a support for the triparm, and adapted to raise said trip varm out of alignment with said'pawlrod, a link connecting one end of said trip lever to the means forretracting said latch rod, so that as the latch rod is retracted andsaid trip arm raised out of Yalignment said pawl rod is permitted tomove rearwardly and actuate saidY retaining pawl.

DUNCAN DQUGLAS MCARTHUR MOFFI'I'I.

